<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <script>
        const num = 10;
        console.log(typeof num); // number
        const str = 'pink';
        console.log(typeof str); // string
        const flag = true;
        console.log(typeof flag); // boolean
        const vari = undefined;
        console.log(typeof vari); // undefined
        const timer = null;
        console.log(typeof timer); // object
        // prompt 取过来的值是 字符型的
        const age = prompt('请输入您的年龄');
        console.log(age);
        console.log(typeof age);
    </script>
</head>

<body>

</body>

</html>
